Components of various industrial devices are often subjected to extreme conditions, such as high impact contact with abrasive surfaces. For example, such extreme conditions are commonly encountered during subterranean drilling for oil extraction or mining purposes. Diamond, with its unsurpassed wear resistance, is the most effective material for earth drilling and similar activities that subject components to extreme conditions. Diamond is exceptionally hard, conducts heat away from the point of contact with the abrasive surface, and may provide other benefits in such conditions.
Cutters and other elements for use in drilling a wellbore have a longer usable life in downhole and drilling conditions if their surface layer is made of polycrystalline diamond (PCD) or another superabrasive material, typically in the form of a polycrystalline diamond compact (PDC), or another super abrasive material compact. Cutters and other elements may contain a PCD layer bonded to a substrate. PCD may be formed at least in part from diamond powder compressed at high temperature and pressure.
The process for forming PCD often involves the use of various additives. For example, cobalt is a substance that may be added for facilitating diamond-diamond bonds in the PCD and for bonding the PCD to a substrate. Such a substance is sometimes referred to in the art of PCD manufacturing as a catalyst or catalyzing material. Substances added to diamond powder used in PCD also include binders and infiltrants. During production of the cutter or other element or before its use in a subterranean operation, the catalyst, infiltrant, or binder may be wholly or partially removed from interstices in the PCD through a removal process, such as acid leaching. PCD from which a substantial amount of catalyst, binder, or infiltrant has been removed is typically more thermally stable than corresponding PCD containing more catalyst, binder, or infiltrant and is thus often referred to as thermally stable polycrystalline diamond (TSP).